Great article on the duality of subtypes

http://www.the16types.info/vbulletin/content.php/243-Compatible-subtypes-by-Meged

EDIT: most of the stuff in that article is pretty damn accurate, at least from my personal experience.

Here are the key takeaways:

• an ENTp-Ti subtype is best paired with an ISFp-Si subtype. Likewise, an ENTp-Ne subtype is best paired with an ISFp-Fe subtype.
• if an ENTp-Ti subtype is paired with an ISFp-Fe subtype, then the overtly expressed emotions of the ISFp will overwhelm and annoy the ENTp-Ti.
• if an ENTp-Ne subtype is paired with an ISFp-Si subtype, then the ENTp-Ne subtype will be annoyed by the down-to-earthness of the ISFp.